Unusual for a television show, Creator John Wells has a very strict policy of no scripts allowed on-set. The actors and actresses have to know their lines by heart.
The show goes to Chicago twice for a week to shoot exteriors, after filming every six episodes on Warner Brothers' sound stages.
Steve Howey, who plays Kev, spent the entire season three recovering from a torn Achilles' tendon.
Woody Harrelson was originally set to star, back when the show was to air on NBC, then HBO, and then Showtime, before dropping out after the success of Zombieland (2009).
A unique show trademark, are the main character's breaking the fourth wall, at the episodes' beginnings, inquiring as to why the viewer supposedly did not view the previous episode, before recap flashbacks are shown, with unaired scenes.
Each child, aside from Liam, identifies with the behavioral roles of children of alcoholics. There is the perfect child or the hero (Debs). There is the rebel or the scapegoat (Carl). There is the clown or the mascot (Lip). There is the lost child or the loner (Ian), and there is the caretaker (Fiona).
According to details written in the early script of the show's pilot episode, Fiona Gallagher was originally supposed to be very average-looking and overweight, with rattier clothes and messy blonde hair; a huge contrast from the slender, brunette beauty (Emmy Rossum).
The cigarette brand "Morley" is used in several episodes. This is the same fake brand from The X-Files (1993).
Allison Janney played Sheila Jackson in the original pilot, but when the producers decided to expand the role, Janney had to drop out, because she was a full-time regular on Mr. Sunshine (2011), so Joan Cusack was cast.
This is an American remake of an English show. The UK counterpart (same title) is set on the Chatsworth council estate, a fictional borough in Manchester. It originally ran from 2004 to 2013 for eleven seasons, and 139 episodes.
Mark Mylod directed the first episode of both Shameless shows, the English one, and its American remake.
The cast admits that sometimes the scripts and story lines are outrageous, even to them.
Ruby Modine (Sierra), who plays Lip's love interest in season seven, previously dated Cameron Monaghan (Ian, Lip's brother) in real-life.
Ed Lauter, who played the school guidance counselor (Dick Healy), got sick in season three. He passed away on October 16, 2013, two weeks shy of his 75th birthday, Lauter died of mesothelioma, after being diagnosed five months earlier in May. His final episode was "Survival of the Fittest", season three, episode twelve.
During the show's third season, Emmy Rossum had the show's writers give Justin Chatwin a fake scene, in which he told his father he was gay. The crew members revealed it was a prank on camera. He played a gay son to a homophobic father on Weeds (2005).
William H. Macy is the only series regular to have ever written (in season two) and also direct (season five) an episode of the series.
Besides playing the leading role of Frank Gallagher, William H. Macy also portrayed Frank Gallagher's twin brother, Jerry.
Early in her career, Shanola Hampton guest-starred as a Pep Squad Pepette on Reba (2001) with Steve Howey. Ten years later, they play husband and wife on this show.
Paul Abbott, who created the original English series, was originally against the idea of an American remake, fearing it would be stereotypically set in the South. He changed his mind, once John Wells told him it would take place in Chicago.
Ethan Cutkosky is slightly older than Emma Kenney, though his character is her younger brother.
When Lip goes to Miami, there is a clip from the movie Bad Boys II where a helicopter is chasing a boat.
Michael Patrick McGill, Cameron Richardson, Janet Varney, and Will Sasso all appeared in at least one episode of the HBO series Entourage (2004), that Mark Mylod also directed.
With the renewal for season 9, it became the longest show in both episodes (108) and seasons of all of Showtime's history.
Jane Levy (who played Mandy in the first season) and Justin Chatwin (Steve/Jimmy) starred together in the 2015 film "Bang Bang Baby."
Justin Chatwin and Emma Rossum has worked together before on the film: Dragonball Evolution (2009) as respectively Goku and Bulma.